Pump or compressor



Jan. 20, 1931.

W. G. E. ROFAFF PUMP OR COMPRESSOR Filed June 1, 1925 nzm A TTOIUVE Y Patented Jan. 20, 1931 PATENT OFFICE WALTER G. E. BOLAI'F, OF ST. LOUIS, MISSOURI PUMP B COMPRESSOR Application filed June 1,

This invention relates to improvements in compressors desi ed more part1cularly for use in the art 0 mechanical refrlgeratlon,

' but, in principle, equally applicable for use a in the general art of displacing liquids and gases, including pumping.

The invention is chiefly concerned with improvements in that type of compressor using double or complementary eccentrlcs,

l0 actuated from a main drive shaft and operating automatically to effect and maintam sealing contact of the rotor with the wall of the-cylinder in its movement over the same. A characteristic feature of the'invention resides in the employment of a single selfaligning bearing located within the 'rotor and co-operating with double eccentrlcs to secure and maintain correct alignment as between the surfaces of the rotor and the cylinder, both as respects parallelism and lane.

A further characteristic feature of t e invention resides in the employment of a blade located in a slot in the wall of the cylinder, and co-operating with the surface of the rotor to effect sealing contact therewith, so as to provide, successively, a compression and exhaust area within the cylinder as the rotor gyrates within the same, together with the use of an elastic medium for forcing the of the rotor.

Preferably, the blade I employ is in the form of a multiple self-packing blade, such as shown and described in my Patent No.

1,280,306, dated October 1st, 1918.

The simplest form of my invention is that in which the same is embodied in a construction designed to act as a pump. Such embodiment is shownin the accompanying drawing, in which Figure 1 is a longitudinal sectional view through a pump constructed according to my invention, and taken on theline 1'-1'of Fig.- ure 2;

Figure 2 is a cross-sectional view of the P m Figure 3 1s a broken sectional v1ew taken on the line 3-3 of Figure 1 showing the ports affording communication between the cylinder chamber and a chamber at the rear blade into sealing contact with the surface- 1925. Serial No. 33,951.

of the blade; and Figure 4 is a view in front elevation of a modified blade construction showing the use of springs for actuating the central wedge.- late of t e blade.

Referrin now to the drawings, the numeral 1 indicates a c linder, which comprises end sections 2, 3, b0 ted to a central annular section 4, the inner surface 5 of which constitutes the workin surface of the cylinder.

The end walls of t e cylinder are provided by flat faces 6 on the inner sides of the membars 2 and 3, which faces project inwardly beyondthe surface 5 of the cylinder to pro- 'vide a working chamber 7. Each of the members 2, 3, is recessed, as indicated at 8,

to provide a space for an anti-friction hearing 9, in which bearings is mounted the drive shaft 10. Located within the chamber 7 is an annular roller or rotor 11, which is mounted on the shaft 10 in such manner as to provide for automatically producing and maintaining a sealing contact with the wall 5 of the cylinder, and also to be self-aligning therewith.

To this end, I provide on the shaft 10, an .eccentric 12, which is circular in cross-sec tion, and mount on this eccentric an' eccentric sleeve 13. That is to say, the sleeve 13 has an eccentric bore which fits on the eccentric 12 so as to be capable of rotating thereon, the construction providing a double eccentric, which functions automatically as a' take-up for the space between the rotor and the cylinder. v

Mounted on-the eccentric sleeve 13 to ex- 5 tend between the same and the inner wall of rotor 11 is a single self-aligning bearing, which supports the rotor. This bearing, in combination with the eccentric sleeve 13, allows universal alignmentof the rotor to the cylinder 'wall, both as to parallelism and plane. In principle, this bearing is the same as that described and claimed in my prior Patent No. 1,441,37 5, dated January 9th, 1923, or in my prior Patent No. 1,632,562, dated June 14th, 1927. It comprises an annular race-way 13a surrounding the eccentric sleeve 13 and grooved on its periphery to provide race-ways for the balls 14;. Surrounding these balls is an annular bearing member 14a, the periphery of which is fiat and in engagement with the inner surface of the rotor 11, and the inner surface of which is transversely machined to the shape of a correct segment of a sphere, this surface being in engagement with the outer surfaces of balls 14. This arrangement allows the rotor to adjust itself parallel to the cylinder walls in any direction, because it is essentially, in principle, a universal joint or bearing. The stuffing box for the end of the shaft which projects through the wall of the cylinder is in the form of a metal bellows 15, one end of which is screwed on the shaft 10, as indicated at 16, and the other end of which bears against an inner wall 17, constituting the outer wall of the bearing recess 8, which wall is provided with a shaft opening 18 of larger diameter than the shaft,

through which the medium being pumped can' pass into the bellows 15, which will, accordingly, expand and force its other end, which is in the form of a packing ring, 19 firmly against the outer side of the wall 17 to make sealing contact therewith and prevent the escape of the medium being pumped. The bellows is located in a chamber 20 cast in the cylinder member 3, which chamber is closed by a plate 21, apertured to permit the driving end of the shaft to pass through it.

Referring to Figure 1, the numeral 22 indicates an inlet or suction port, through which the material to be pumped may pass or be sucked in, in the operation of the pump, and the numeral 23, an outlet from the cylinder, which is provided with any suitable form' of check valve 24. The ports 22 and 23 are provided in castings formed integral with the cylinder, and intermediate these orts, a casting 25 is provided in which is coated a slot 26, which is of the length of the cylinder chamber 7, and in this slot is located a blade--27 which, as stated, is preferably of the self-packing type of my prior patent. This blade may be briefly described as comprising a back-plate 28 having at its outer end a shoulder '29, extending throughout the length, and of the width of the slot, on which back-plate are mounted two tapered packing plates 30 and 31, and in the wedge-shaped space between these packing plates, a freely-movable wedge-plate 32. This blade may be held in sealing contact with the surface of the rotor 11 by any suitable elastic means, such as a spring or fluid, but I prefer the latter. To this end; the outer end of the slot 26 terminates in a small chamber 33, with which communicates ports 34 drilled in the wall of the blade-slot 26 and leading from the cylinder chamber 7. These ports are located just beyond the outlet 23, or at substantially the point of greatest compression within the chamber 7. According to this construction, when the pump is placed in operation, the medium being pumped passes through the ports 34 into the chamber 33 and forces the inner edge of the blade 27 into sealing contact with the surface of the rotor and, of course, maintains such contact.

In order to facilitate the direct pressure of the fluid upon the central wedge-plate 32, an opening 36 may be provided in the shoulder 29 to permit access of the fluid to the wedgelate, which, accordingly, operates to force t e packing plates 30 and 31 into enga ement with the end walls of the cylinder to form sealing contact therewith, which contact is automatically maintained during the operation of the pump,

Referring now to the action of the double eccentric, comprising the shaft eccentric 12 and the eccentric sleeve 13 mounted on the same, when the shaft 10 is rotated, the eccentric 12 immediately acts upon the eccentric sleeve 13, which, in turn, acts upon the bearing 14, and the latter, the outer member of which is in the form of an. annulus, acts upon the inner surface of the rotor, forcing it outward into engagement with the wall 5 of the cylinder. It may require a few revolutions of the shaft before the rotor is thus adjusted, and, 'of course, the faster the shaft rotates, the quicker the eccentrics will be movedto the p'bsition in which the rotor is forced into sealing contact with the yvall of the cylinder.

' It will beat once recognized'that the action of the double eccentrics not only enables me to secure a gyroscopic movement of the rotor within the cylinder and in contact with the wall thereof, which, in itself, is not new; but that I am enabled also to maintain a constant automatic adjustment of the rotor to compensate for wear; and at the same time, by reason of the self-aligning bearing located within the rotor, I likewise secure and maintain an automatic alignment of the surface of the rotor with the inner surface of the cylinder, so that the contact is uniform and constant throughout the length of said surfaces. Furthermore, the contact pressure'of the rotor with the wall of the cylinder is in direct proportion to the resistance offered to the movement of the rotor by the degree of pressure within the chamber 7, due to the resistance offered by the substance being pumped. In operating under great resistance, as in pumping a liquid to a considerable height, without the selfcompensating feature of my invention, such resistance could be offered that the medium being pumped would be forced between the rotor and the wall of the cylinder, and thus lower the efliciency of the pump. In the arrangement described, however, this becomes impossible, as, with increased resistance to the movement of the rotor, the latter automatically is forced into firmer contact with the Wall of the cylinder by the action ing chamber, changin of the eccentrics. In operation therefore, there can never be less than su cient pressure to provide a sealing contact of the surface of the rotor with the wall of the cylinder. 4

By by-passing a portion of the fluid being pumped to the chamber 33 at the upper side of the blade 27, the lower or working edge of the latter is yieldingly held. in sealing contact with the surface of the rotor. That. is to say, the pressure on the blade is directly responsive to the pressure within the workfrom maximum to minimum in synchromsm with the varying pressure within the working chamber of the cylinder. In Figure 4, I have shown the use of springs 37 interposed between the shoulder 29 and the top of the wedge-plate 32, which operate to force thelatter inward and the wedge-plates 30 and 31 laterally into engagement with the end walls of the cylinder. In this construction, the wedge-plate 32 is slightly shortened to provide space for the SprlngS.

Any desired manner of lubricating the interior of the pump may be employed, and

. I have shown at 38 oil cups located on the cylinder at a plurality of points and communicating with the interior thereof to supply oil to the working parts. If oil were ing pumped, of course, the lubrication would be effected automatically. In certain applications, oil could be simply supplied to the interior of the pump from time to time and the surplus be expelled in the pumping operation.

I wish it understood that while my invent1on primarily contemplates a rotor having a gyroscopic movement within a stationary cylinder, I do not, as to certain features of the invention, wish to be limited to the use of a stationary cylinder, of to a rotor which gyrate's.

It should be further stated that in referring to the self-aligning bearing as producing an alignment between the rotor and cylinde'r, this contemplates not only an alignment as between the surface of the rotor and the wall of the cylinder, but also an exact alignment of the ends of the rotor-with the ends of the cylinder.

While I have described my invention in its embodiment in agyratory compressor or pump, I wish it understood that my improved device is equally applicable for use as a prime mover, in which application compressed air or any other medium under pressure could be supplied through the suction side of the device, or, by removing the valve, such pressure medium could be supplied through the exhaust port of the machine. Such vadaptations and changes are well known to those skilled in the art, and are ed for gyroscopic movement within the cyl:

inder and in rolling engagement with the wall thereof, and means for aligmng the rotor with the cylinder independent I v 2. In a machine of thecla'ss described, in

y of the shaft.

combination with'a stationary cylinder, a rotor mounted for gyroscopic movement within I the cylinder, means for lmp arting movement to said rotor to cause it tofunctionally co operate with the wall of said cylinder, andmeans for aligning the-rotor with the cylinder independently of the shaft.

3. In a machine of the class described, in combination with a cylinder, a rotor mounted for gyroscopic movement within the cylinder and in rolling engagement with the wall thereof, and means located within the rotor for aligning the rotor with the cylinder independently of the shaft.

4. In a machine of the class described, in combination with a cylinder, a rotor mounted for gyroscop-ic movement within the cylinder and in rolling engagement with the wall 5. In a machine of the class described, in

combination with a cylinder, a rotor mounted for gyroscopic movement within the cylinder and in rolling engagement with the wall thereof, and means located within the rotor for automatically aligning the rotor with the cylinder independently of the shaft.

6. In a machine of the class described, in combination with a cylinder, a drive shaft mounted in the cylinder, a rotor mounted in the cylinder, means on said shaft for imparting a gyroscopicmovement to the rotor, and self-aligning means interposed between said shaft and rotor for aligning the latter with the cylinder independently of the shaft.

7. In a machine of the class described, in combination with a cylinder, a drive shaft mounted therein having an eccentric, an eccentric sleeve rotatably mounted on said eccentric, a hollow rotor mounted in said cylinder, and a self-aligning bearing interposed between the inner wall of said rotor and said posed we ge-plate, a chamber opening from said slot at the outer end of the blade, and a conduit aifording communication between said chamber and the workin chamber of the cylinder, whereby said cham er will receive, under pressure, the medium being acted on Within the cylinder, said blade will be maintained in contact with the surface of the rotorand said Wedge-plate will 0 erate, under the pressure of said medium, to orce the packing plates into engagement with the end walls of the cylinder.

9. In a machine of the class described, in combination with a stationary cylinder, a rotor mounted for gyratory movement within the cylinder, a blade slidably mounted in a slot in the wall of the c linder and co-operating with the surface 0 said rotor, said blade comprising two packing plates and an interposed wedge-plate, and means for yieldingly forcing the inner edge of the blade into contact with the surface of the rotor and the wedge-plate inward between the packing plates to force the latter into sealing contact with the end walls of the cylinder.

10. In a machine of the class described, in combination with a stationary cylinder, a rotor mounted for ratory movement within the cylinder, a bla e slidably mounted in a slot in the wall of the c linder and co-operating with the surface 0 said rotor, said blade comprising two packing plates and an interposed wedge-plate, and means for forcing the inner edge'of the blade into sealing contact with the rotor and for simultaneously moving the wedge-plate inward to force the packing plates into sealing contact with the end walls of the cylinder.

. In testimony whereof, I have hereunto set I m hand.

y WALTER G. E. ROLAFF. 

